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MIRLangRef: Describe the syntax for machine instruction names and flags.

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Alex Lorenz 2015-08-21 17:26:38 +00:00
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docs/MIRLangRef.rst
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@ -200,10 +200,49 @@ specified in brackets after the block's definition:
.. TODO: Describe the way the reference to an unnamed LLVM IR block can be
preserved.
Machine Instructions
--------------------
A machine instruction is composed of a name, machine operands,
:ref:`instruction flags <instruction-flags>`, and machine memory operands.
The instruction's name is usually specified before the operands. The example
below shows an instance of the X86 ``RETQ`` instruction with a single machine
operand:
.. code-block:: llvm
RETQ %eax
However, if the machine instruction has one or more explicitly defined register
operands, the instruction's name has to be specified after them. The example
below shows an instance of the AArch64 ``LDPXpost`` instruction with three
defined register operands:
.. code-block:: llvm
%sp, %fp, %lr = LDPXpost %sp, 2
The instruction names are serialized using the exact definitions from the
target's ``*InstrInfo.td`` files, and they are case sensitive. This means that
similar instruction names like ``TSTri`` and ``tSTRi`` represent different
machine instructions.
.. _instruction-flags:
Instruction Flags
^^^^^^^^^^^^^^^^^
The flag ``frame-setup`` can be specified before the instruction's name:
.. code-block:: llvm
%fp = frame-setup ADDXri %sp, 0, 0
.. TODO: Describe the parsers default behaviour when optional YAML attributes
are missing.
.. TODO: Describe the syntax of the machine instructions.
.. TODO: Describe the syntax for the bundled instructions.
.. TODO: Describe the syntax of the immediate machine operands.
.. TODO: Describe the syntax of the register machine operands.
.. TODO: Describe the syntax of the virtual register operands and their YAML